**8. Conclusion**

**e.** Destroy method is invoked: The web container calls the destroy method before removing the servlet instance from the service. It gives the servlet an opportunity to clean up any

**Figure 15.** Various stages in request and response mechanism of servlets. (a) Clients request handling carried out by web container. (b) Object formation. (c) Calling servlet thread. (d) Thread execution. (e) Submission of response. (f) Final

response toclient.

resources like memory, thread etc. **Figure 16** shows life cycle methods of servlets.

20 New Trends in Industrial Automation

In the past couple of years there has been a development of enthusiasm for versatile platform innovation and a few stages have been developed and innovated to allow more independencies in programming platform. In this chapter we have surveyed and researched the various computing environment provided for remote execution that has incurred the need of mobile codes, intelligent agents, autonomous objects, etc. raising issues with flexibility, efficiency and security in present system that can promises to resolve existing problems and add on more facilities like remote execution, auto-scheduling and many more. Some of them have just been utilized for look into purposes while others have been conveyed as business items. A few technologies that incorporated in evolution of mobile agents have been discussed on the basis of the usefulness of have been displayed in this exploration.
